You can train perfectly and still spin your wheels if your nutrition isn't pointed at the goal. For building muscle, that means a modest calorie surplus and enough protein to support new tissue. Here's how to set your numbers in about five minutes.

Step 1: Find maintenance calories

Maintenance is the intake that keeps your weight stable. The fastest estimate is a TDEE formula based on your stats and activity — start with our TDEE calculator. Treat the output as a starting hypothesis, not gospel: real maintenance is whatever actually holds your weight steady over two weeks.

Step 2: Add a lean-gain surplus

To gain muscle you need surplus energy — but more surplus does not mean more muscle. Past a point, the extra just becomes fat. A surplus of roughly 10% over maintenance (about 250–400 kcal for most people) is plenty.

The dirty-bulk tax

Huge surpluses add weight fast, but most of it is fat you'll have to diet off later — eating into the muscle you built. Slow and lean wins the year.

Step 3: Set protein first

Protein is the macro with the most evidence behind it. Aim for 1.6–2.2 grams per kilogram of bodyweight (about 0.7–1.0 g per pound). Within that range, total daily intake matters far more than timing or "anabolic windows."

For an 80 kg lifter, that's roughly 130–175 g of protein per day.

Step 4: Fat floor, then carbs fill the gap

Set dietary fat at a floor of about 0.8 g/kg to protect hormone production, then assign the remaining calories to carbohydrate — your primary training fuel. More carbs generally means better, harder sessions, which is exactly what you want while gaining.

Tip

Don't want to do the arithmetic by hand? The macro calculator sets protein, fat, and carbs from your goal and bodyweight in one step.

Step 5: Adjust based on real data

Your starting numbers are a guess. Let the scale referee:

Gaining too fast (more than ~0.5–1% bodyweight/month): trim carbs by ~10%.
Not gaining at all over 3–4 weeks: add ~150 kcal of carbs.
Strength climbing, waist stable: you're dialed in — leave it alone.

Let the app do the watching

MuscleBuddy tracks your rolling weigh-in average and flags when your surplus has drifted too hot or too cold — so you adjust on data, not vibes.

The whole thing in one paragraph

Estimate maintenance, add ~10%, set protein at ~1.8 g/kg, keep fat above 0.8 g/kg, fill the rest with carbs, and recheck against the scale every month. That's a muscle-gain diet. Everything else is optimization at the margins.

Get your protein, carb, and fat targets in one click.

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How to Calculate Your Macros for Muscle Gain (Without Overthinking It)